Error F18 in the Bosch washing machine

F18 in the Bosch washing machine is an error code of the self-diagnosis system of some models of this brand. Not on all Bosch washers this error occurs. It happens that in a similar situation, the Bosch washing machine gives the code E18, and sometimes d02. Everything will depend on which version of the self-diagnosis system is embedded in the software of a particular model. But it doesn’t matter what kind of code of these three your “home assistant” of the German brand will give out, the main thing is to correctly decrypt it and understand what kind of malfunction caused it.

Code Decryption

So, mistake F18 in the Bosch washing machine appears if the “home helper” spends too much time draining the water. The fact is that the program of the machine contains the minimum and maximum time intervals for which the washer must remove the waste water. If during the maximum allotted time the drain is not carried out to the end, the control module gives a command to stop the wash and displays the code F18.

If the Bosch washer has a display, then error F18 is colorfully displayed on it. If there is no display, the machine informs the user about this error with the help of a burning indicator of 1000 revolutions and an indicator of 600 revolutions.

Why Bosch brand washer drains the water too slowly, what is the reason for this behavior of technology. In fact, there can be quite a few reasons for this.

1. One of the main reasons is the incorrect connection of the drain hose when installing the washing machine.
2. Error F18 can be caused by blockages in the pump, waste filter, drain pipe, and hose.
3. The same problem occurs when the pump and pressure switch break down. In the first case, the machine simply cannot pump water from the tank, but in the second, the control module does not receive data on the water level in the tank and immediately generates an F 18 error.

Incorrect installation

If you are installing a Bosch washing machine yourself, the more you do it for the first time, you need to pay attention to how to connect the drain hose of the washing machine to the sewer. And the point here is not even the way to connect the hose to the sewer, but to properly position the hose itself.

What do we mean? The hose must be slightly bent when connected to the sewer. It is not permissible to connect the drain hose to the interference fit. If the length of the standard hose that is included with the Bosch washing machine is not enough, you can extend it, or buy a longer hose. However, it must be understood that the longer the drain hose, the greater the load on the pump, the greater the load, the less the working life of the part.

The connection height relative to the legs of the washing machine should not be more than 1 meter, the hose should not be “laid” too low either. The optimum height of the connection point is 40-60 cm.

Also, make sure that the drain hose is not pinched by anything or even kinked, as this will unambiguously hinder or stop the discharge of waste water.

Various blockages

Clogs can become a real “scourge” of an automatic washing machine brand Bosch, and any other. If draining is difficult or absent and the washer generates an F18 error, be aware that it is very likely that some serious blockage is to blame. How will we look for this blockage?

• At first, we will not go into the washing machine body and disassemble something there. Let's see where it can be done the easiest way, namely, look into the hole in the trash filter.
• After checking the trash filter, disconnect the drain hose and check it, maybe the blockage is hiding there.
• At the next stage, we will need to turn off the washing machine, pull it out, remove the powder receptacle and lower the Bosch machine on the left side wall. Through the bottom, you can easily get to the pump and the drain pipe, because it is there that the blockage can also “hide”.

After checking all that is possible and making sure that there are no blockages, you can proceed to the next stage of the search for the cause of the F18 error - checking the pump and pressure switch. By the way, it will now be more convenient for you to do this, since the machine is already disconnected and disassembled. Moreover, you already got access to the pump through the bottom of the machine, so it would be most reasonable to start with the drain pump.

Pump and pressure switch

Checking the drain pump must begin with its dismantling. We pull off the clamps that connect this part to the nozzles. Next, unscrew the external screws that connect the pump to the trash filter (screws around the hole of the trash filter). Now it remains only to disconnect the wires, remove the pump from the nozzles and pull it out of the washing machine.

We spin up the pump and examine its insides, mainly paying attention to the state of the impeller. If the impeller is intact, nothing is wound on it and there is no dirt, most likely the pump mechanics are in perfect order, we proceed to check the electrics of the drain pump. We take a multimeter and call the contacts of the wires that feed the pump, then we test the drain pump itself.

Perhaps after all the tests, the F18 error will not go away. In this case, you will have to check the water level sensor, which is located under the top cover of the Bosch washing machine. You can read about how to check and repair this sensor in the article. Checking the pressostat of the washing machine.

In conclusion, we note that we were able to understand the nature of the F18 error in the Bosch washer, list the potential causes of its occurrence, and also talk about finding and eliminating the causes of this error. We hope you find this information useful, good luck!